OOS 50-3 - Legacies of natal sources and dispersal histories: Implications for connectivity in a reef fish metapopulation

Friday, August 12, 2011: 8:40 AM
14, Austin Convention Center
Jeffrey S. Shima, School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand and Stephen E. Swearer, Department of Zoology, University of Melbourne, Melbourne, Australia

In temperate reef systems, larval dispersal typically connects fragmented populations, and larval quality may be shaped by developmental history at the natal reef (e.g., parental effects) and/or by conditions in the pelagic environment (e.g., food, temperature, hydrodynamics, predator regime).  We use otoliths of the common New Zealand triplefin (Forsterygion lapillum) to reconstruct the early life histories and evaluate whether larval quality is a function of natal populations, dispersal histories, or both.  We used image analysis to quantify otolith traits and to reconstruct 5 larval phenotypes (pelagic larval duration, size-at-hatch, early larval growth, late larval growth, and an instantaneous larval growth rate), followed by a principal components analysis to derive a composite measure of larval quality.  We used LA-ICPMS to quantify otolith microchemistry, followed by a set of cluster analyses (based upon 13 statistical descriptors of time series for each of 11 trace elemental ratios) to identify and characterize two putative natal “source populations” and two putative “larval dispersal histories”. 


We evaluated the relationship between larval quality, source populations and dispersal histories using 2-way ANOVA and determined that larval quality of F. lapillum is a function of larval dispersal history and not source population identity.   Overall, our results suggest that conditions in the pelagic larval environment shape larval quality and potentially mediate metapopulation connectivity for a temperate reef fish. 

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